Conduit Bender Marks:

It's slightly different on each former. Get a set square, put that on the outside edge of the former, sat on the pipe and thats the outside of the bend.

Guides which show it better than a written description here:

Bender instructions

Another: Bender instructions 2

Of course the two types work slightly differently.

I also have some course handouts. However, I tip my hat to anybody who can bend a pipe to the exact dimensions first time.

Naturally, if you just need an L-shape, you can trim the ends afterwards.

For things like an S-bend, my approach has involved a degree of trial and error. So put two marks a certain distance apart which is your first estimate guess. Put the mark at the edge of the hook which holds the pipe. Make the bends. If they are correct, have a cup of tea and a biscuit. If not, adjust the distance between the marks. Repeat as necessary.

I hang my head in shame, but it does work, albeit with some waste.

Brings back memories for sure!! Didn't have any issues with setting the Former with set square as previously described, but was always amazed by some of the old electricians that just used a block of wood with a hole in it and just as accurate!

Cheers GTB

Thank you for your replies. I'm aware how to use the back of the former, in fact we just used to eye the mark down, and it worked pretty well.

There was a mark for the centre of the bend and one when the back of the bend was on top.

I've read mark 50mm from the front of the former, but that doesn't appear to be anywhere near.

Trial and error it is then...:-)